Perforating method and apparatus



June 3, 1941- F. J. CHANDLER PERFORATING METHOD AND APPARATUS Filed March 11, I940 2 Sheets-Sheet 1 I will flaw? June 3, 1941. F. J. CHANDLER PERFORATING METHOD AND APPARATUS Fi led March 11, 1940 2 Sheets-Sheet 2 Patented June 3, 1941 UNITED STATES PATENT OFFICE PERFORAT ING METHOD AND APPARATUS Frank Jermain Chandler, Toledo, Ohio Application March 11, 1940, Serial No. 323,313

10 Claims.

My invention relates to the perforating of sheet materials composed partly or wholly of rubber or the like, and has reference more particularly to a method of and machine for puncturing with sufficient localized heat at the puncture place to facilitate penetration and preserve the perforation.

In many cases, for example when used for clothing or upholstering, it is desirable to provide sheet rubber, rubber coated fabrics, laminated rubber and fabric sheets or other similar materials with tiny openings therethrough for ventilation or breathing as it is commonly called, and because of the elasticity and subsequent processing of the rubber it is dimcult to provide satisfactory perforations which are suificiently small to be reasonably inconspicuous and which are nevertheless sufficiently permanent to be preserved in the final product. Materials composed of or including rubber are preferably perforated before the rubber is cured and softening of the rubber which occurs in the subsequent curing naturally tends to impair and eliminate the openings.

The principal objects of my invention are to provide an improved method and apparatus whereby sheet rubber, fabrics laminated or coated with rubber, or other similar materials may be made with tiny openings therethrough suitable for ventilation or breathing; to form the openings so that they extend completely through the sheet material; to insure uniformity and perma nence of the openings; to avoid impairment or elimination of the openings in subsequent processing of the sheet material; to permit provision of such perforations in any fabric layers of the sheet material without mutilation or injury to the fabric; and to permit the producing of such openings in plastic pattern surfaced sheets without marring or defacing the pattern surface thereof, these and other objects being accomplished as pointed out hereinafter and as shown in the accompanying drawings in which:

Fig. 1 is a view of the delivery side of a perforating machine made in accordance with this invention;

Fig. 2 is an enlarged vertical sectional view taken on the line 2--2 of Fig. 1;

Fig. 3 is an enlarged horizontal sectional view on the line 33 of Fig. 2;

Fig. 4 is an enlarged detail of a portion of the sectional view shown in Fig. 2;

Fig. 5 is a fragmentary side view, partly in section of the die plate;

Fig. 6 is a fragmentary side view of one of the feed rolls for advancing the sheet material through the machine;

Fig. 7 is a view similar to Fig. 3 showing a modified needle heating arrangement;

Fig. 8 is a detail section of the Fig. 7 structure with diagrammatic representation of a controller which may be employed for intermittently heating the needles;

Fig. 9 is a detail sectional view somewhat similar to that of Fig. 4, showing another manner of heating the needles;

Fig. 10 is an enlarged fragmentary sectional view illustrative of material prepared with tiny openings or breathing pores in accordance with this invention; and

Fig. 11 is a detail view showing a modified form of needles that may be employed.

In the accompanying drawings which show a preferred embodiment of the invention, a ma chine is disclosed comprising an elongated needle carrier which is vertically reciprocable to and from a work support over which the sheet material to be perforated is periodically advanced, the needle carrier being provided with a row of depending sharp pointed heated needles which on each downward stroke of the needle carrier penetrate clear through the sheet material on the work support and form a row of tiny openings or breathing pores across the width thereof, the sheet material being advanced a predetermined distance as the needle carrier is raised so that the repetitive operation of the needle carrier forms succeeding spaced rows of tiny openings or breathing pores throughout the length of the sheet material.

The machine comprises spaced end standards ii and i2 rigidly connected at their respective upper and lower ends by frame members it and it, and there is also a cross beam l5, which may be of I form as shown, extending between the frame members it and i2 and rigidly secured thereto at a suitable elevation to support the work, a die plate It being fixedly mounted on the top of this cross beam l5 and having a transversely rounded top surface as shown in Fig. 2 over which the sheet material H is fed and by which it is supported in the perforating operation.

Above this die plate I6 is reciprocably mounted the needle carrier indicated as a whole at E8, to which a row of work perforatin needles l9 are attached. Said carrier I8 comprises a beam 20, which may be of I form as shown in Fig. 2 and is slidably mounted at its opposite ends on suitable guide rods 2! to move to and from the die plate It. These guide rods 2| are secured at their lower ends to the beam I 5 and at their upper ends to brackets 22 on the standards It and i2.

A shaft 23 is journaled above the die plate IS in bearing brackets 24 hung from the upper frame member [3 and this shaft extends through a bearing 25 in the standard H and is provided on its outer end with a large gear 26 in mesh with a pinion 21 on the end of a shaft 28 which extends across the machine and is Journaled in the upper ends of'the standards II and I2. Said shaft 28 has on its other end a combined flywheel and pulley 29 engaged by a belt 30 which is operatively engaged with a pulley 3| of a motor 32 or other convenient source of power by which the shaft 23, through the connections just described, is rotated at a comparatively slow s eed.

This shaft 23 has a pair of eccentric disks 33 fixed thereon in spaced relation and each embraced by an eccentric strap 34 of an eccentric rod or arm 35 and the lower ends of these arms 35 are pivotally connected at 36 between pivot lugs 31 on the top of the I-beam 20 of the :needle carrier so that in rotation of the shaft 23 the needle carrier l8 and its needles l9 are reciprocated to and from the die plate I6.

The perforating needles I9 are of small di-,

ameter so as to make small holes andsharp pointed to penetrate readily without tearing or mutilating the sheet material and are mounted on the carrier I8 in suitable spaced relation according to the spacing of openings desired in the sheet material, and to insure penetration of the needles i9 entirely through the work and also to afford a length of time during which the needles remain in engagement with the perforations, the die block I6 is provided with small openings 38 located directly under the needles I9 to accommodate the needle ends, and the needles are arranged to have a range of reciprocation such that at the end of each down stroke the needle ends engage in the openings 38.

These needles I9 are mounted in a row in spaced relation in a holder 39 which is secured to the under side of the carrier beam 20 and said needles have a stripper plate 40 cooperating therewith which has openings 4i therethrough corresponding to the needles i9 and through which the needles are projected in the perforating operation. This stripper plate is supported by stems 42 which are fixed thereto and extend upwardly through openings in the holder 89 and in the lower flanges 43 of the I-beam 29 and these stems are provided with nuts 44 thereon or other suitable means which engage the flanges 43, the stems 42 being engaged loosely in the openings of the holder 39 and flanges 63 so that the stems are free to move axially thereon. Light coil springs 45 are interposed between the nuts 44 of the stems and the upper flange of the beam 20 to hold the stripper plate normally in the lowermost position substantially at the points of the needles i9 and as the latter are depressed to engage the work on the die block the stripper plate 40 engages the top of the work thereon and is held thereagainst by the compression of the springs d5 while the needles are propelled downwardly through the work and as the needles are elevated the stripper plate remains engaged with the work until the needles are withdrawn therefrom.

Rubber and rubber like materials, especially in the uncured condition, offer a high frictional resistance to penetration by perforating needles and because of the elasticity and tackiness of the rubber, the small holesare likely to close after the needles are withdrawn or the openings may be mutilated. or deformed by adherence of the rubber to the needles. Moreover, these tiny openings or pores may be impaired or closed in subsequent handling and processing, especially upon vulcanization of the rubber during which the rubber is softened and becomes plastic and flowable.

To overcome these difficulties in providing such materials with tiny breathing pores or openings. I heat the perforating needles to a suitable temperature so that they not only penetrate and withdraw readiLv from the rubber and leave openings therethrough which are perfectly formed, but the heat is such to cause an incipient vulcanization of the rubber immediately aroimd the openings or to impart thereto a suflicient set so that the tiny openings are sufllciently permanent to withstand subsequent handling and processing of the material without impairment or closing, care being taken however, to control the heat so that it is not sufficiently high to burn the rubber or fabric.

. the needles l9 and a rheostat 54 or other suitable current controller is provided to regulate the current supply to the resistance 48 so that the needles may be maintained at any desired temperature.

It is desirable to avoid communication of heat to the stripper plate 40 which comes in contact with the work and accordingly the stripper plate openings 4i are made sufficiently larger than the needles I9 as shown in Fig. 4 to avoid contact therewith and provide an air circulation space therebetween for minimizing communication of heat from the needles to the stripper plate. Moreover the stripper plate may be formed at each side of the row of needles with passageways 55 therethrough connected by flexible tubing 56 with a source of circulating cold water or other cooling medium which is circulated through the passageways 55 to keep the stripper plate cool.

For feeding the material to be perforated through the machine a pair of rollers 51 and 58 are rotatably mounted at one side of the I-beam i5 in brackets 59 on said beam and these rollers engage therebetween the material I! which is led thereto over the die plate l6 from a pair of idler rollers 6d and ti which are located at the other side of the I-beam l5 and may likewise be rotatably mounted on brackets carried by said I- beam, the material being supplied to the rollers $6 and M from any suitable source.

The set of rollers 5'5 and 58 are arranged to yieldingly engage the material it therebetween in any well known manner with suiflcient tension to advance the material, the yielding engagement thereof being preferably adjustable to regulate the pressure on the material, and one of these rollers has the shaft t2 thereof extended through a bearinginthe standard I I and provided at its outer end with a ratchet wheel 63 engaged by a ratchet mechanism 64 which in turn is connected by a link 65 with an arm 66 on the needle carrier 18 so that in the upward movement of the needle carrier It the shaft 62 and its roller are rotated sufficiently to advance the material I I over the die plate the desired distance that the succeeding rows of perforations are to be spaced apart. Obviously the advancing movement of the material I! should not occur until the needles l9 are withdrawn from the material on the die plate i6 and accordingly the ratchet mechanism 64 has suflicient lost motion or delayed action on the uprising stroke of the needle carrier so that the needles l9 are disengaged from the material ll before the advancing movement of the material begins.

The idler rollers 60 and BI likewise are arranged to engage the material I-l with a yielding tension which is preferably adjustable to avoid any undue pressure on the material, minimum tension of these rollers 60 and iii as well as of the other rollers 51' and 58 being especially desirable in the case of embossed or pattern surfaced material li to avoid any impairment of the embossing or pattern surface.

The material to be perforated may be sheet rubber, fabric coated or laminated with rubber or other desired material, a composite sheet of rubber Eil with attached fabric tit lamination being shown herein for purposes of illustration and the exposed surface of the rubber lamination ti may have a design or pattern embossed thereon.

In the operation of the device and in accordance with the method hereof, this material is fed between the rollers 60 and ti over the die plate it and between the rollers 57 and Si? which latter rollers, in each uplifting stroke of the needle carrier 20, advance the material across the die plate a predetermined distance.

Ihe rheostat 56 is adjusted to regulate the supply of currentto the heating element d8 so that the needles l9 are maintained at the proper temperature to penetrate through and withdraw readily, from the rubber laminated material it and also so that the heat of the needles is sufficient to cause a slight incipient vulcanization of the uncured rubber of the lamination til immediately around the perforation, the extent of projection of the needles I!) through the material i'i into the die plate openings 38 being such to insure openings clear through the material and duration of engagement of the needles with the openings to communicate suiiicient heat to the rubber for this purpose, and it is to be noted that the needles penetrate straight through the material at right angles to the surface thereof.

Upon each down stroke of the needle carrier the heated needles penetrate'clear through the sheet material ii thereby softening and spreading the rubber 61 at the perforation to form the openings 69, a row of which are made across the width of the sheet, and as the needles are sharp pointed they penetrate the fabric (it without mutilation thereof, the fabric threads being merely spread apart by the needles to form the openings therethrough. At the same time the heat of the needles I 9 imparts to the softened rubberimmedlately around the openings 69 an incipient vulcanization to an extent sufficient to form ,a sort of thin ferrule iii of semi-set rubber which imparts sufficient permanence to the openings 69 so that they are preserved throughout subsequent handling and processing of the material. Moreover the softened and semi-set rubber around the openings 69 is at the same time combined sufliciently with the spread apart threads of the fabric at the openings to preserve the openings through the fabric so that in the final product fine openings or breathing pores entirely through the composite material are assured.

In the downward stroke of the needle carrier, the stripper plate M is engaged against the top of the material Ill and remains engaged therewith while the needles I!) penetrate through and are withdrawn from the material H, the springs 45 yielding at the time to permit the needles to be projected downwardly through the stripper plate and holding the stripper plate against the material l'i until the needles are withdrawn therefrom.

This stripper plate is kept cool, by water circulation through the passageways 55 if necessary so that it can have no softening effect on the rubber of the material i'l while in contact therewith and moreover the springs M are preferably arranged to impose a sufficiently light resistance to upward movement of the stripper plate so that the stripper plate pressure on the material ii! is such, especially when the latter has an embossed or patterned surface, that the material it or pattern surface thereof is not impaired by the stripper plate pressure.

It will be understood from the above that the sheet material H is not heated generally in the perforating operation but that as the needles only are heated there are merely isolated applications of heat to the material locally at the places where the perforations are made.

It will be noted in Fig. 2, that the direction of the material it in its travel to and from the stripper plate is approximately tangential thereto so that the material. if contacts with the stripper plate only at the top hereof, and in order to avoid any pressure against the material it at the places where the openings $9 are formed the die plate I ii preferably has a transverse groove it (see Fig. 5) across the top thereof at each' place where the openings 38 are formed and the rollers 5i and 56 are also preferably provided with circumferential grooves i2 in alignment with the grooves ll of the stripper plate it so as to eliminate direct pressure on the material ill at the places where the openings as are formed and thereby contribute to the preservation of the openings against impairment which might otherwise be caused by wiping movement of the margins of the openings 69 against the die plate it; or pressure immediately at such margins against the material, especially while the rubber is in a softened condition from the heat of the needles l9.

Instead of employing a resistance embedded in insulating material as in Figs. 2, 3 and 4, for heating the needles, headed needles as shown at 53 in Fig. 8 may be employed which are engaged through openings it in a strip 75 of insulation with another strip iii of insulating material covering the heads H of the needles and clamped thereagainst.

Short segments 18 of electrical resistance material are interposed between adjoining needles and extend under the needle heads Ti and end segments 18 and are also provided, the inner ends of which extend under the heads Tl of the respective end needles l3, and the clamping engagement of the insulating strip 16 against the needle heads holds them in contact with the segments 18, 19 and 80. The end segments 19 and 80 have terminals connected to conductors BI and 82 which lead to a source of electric current, the supply of which to the series of resistance segments l8, l9 and 80 may be controlled by a rheostat 83 to regulate the temperature of the needles. Obviously instead of employing the separate segments 18, it and so a continuous strip of electrical resistance material may be employed and merely provided with openings through which the needles 13 extend with the needle heads TI clamped by the insulating strip 16 against the said strip.

With the above segment or strip electric resistance the needles, which are of electrical conducting material, are necessarily in electrical conducting relation to the heating segments or strip, and the die plate it should be made of electrical insulating material or if preferr d the openings thereof may be insulated as shown in Fig. 8 by ferrules 84 of insulating material. Likewise the stripper plate Ht may be made of insulating material or have the holes 4i thereof similarly insulated, although this is not so essential because of the fact that the holes M of the stripper plate are sumciently larger than the needles it so that they do not contact therewith.

A timing device may also be employed with either electrical needle heating means to heat the needles at intervals which may be arranged to occur in a desired timed relation with the penetration of the material l? by the needles. Such an intermittent heating device is shown somewhat diagrammatically in Fig. 8 and comprises a rotary disk 85 of insulating material having a conductor segment 86 on the periphery thereof with which a brush 8? is arranged to make content during a certain period of each revolution of the disk 85. This disk 85 may m mounted on the eccentric shaft 23 or operated from the eccentric shaft as for example through a belt 88 which engages a pulley 89 on the shaft 23 and a pulley 90 of the same size on the shaft of the disk 85 so that the latter rotates at the same speed as the eccentric shaft 23 and the segment 86 is accordingly in contact with the brush 8? during a certain period of each revolu tion of the eccentric shaft. One of the conductors through which current is supplied to the eletrical resistance which heats the needles leads through the segment and brush interrupter, for example the conductor 82 from a terminal of the resistance leads to the'segment t6 and the conductor 85 leads from the brush 8? to the source of electrical supply and with these connections current is supplied to the needle heating resistance only during the time that the brush 8'! is in contact with the segment Any other convenient means of heating the needles may be employed, as for example a gas supply pipe 92 may be secured by clamps 93 to the under side of the needle holder 60 so that it extends along the row of needles and said pipe 92 may have an orifice 8d opposite each needle 95 to produce an individual gas flame as directed against the respective needle. The needle holder 9'5 of course, in such case does not have the cavity 59 of Fig. 4 nor the electrical insulation thereof, but instead the shanks iii shown in Fig. 9.

The needles l9 may be arranged to effect the advancing movement of the material l1, instead of employing rolls 5'! and 58 for this purpose, in which case the group of needles it have, in addition to their vertical reciprocatory movement, a reciprocating movement in the direction of travel of the material ll of an extent suflicient to advance the material for each successive row of perforations. In such case, instead of using round needles is, the needles may be of ,oval cross section as shown at Hill in Fig. 11 with the major axis thereof transverse to the direction (indicated by the arrow llll) in which the material is moved by the needles. The needles I00 necessarily exert a pull on the material I! to advance same and as this may tend to distort the opening and increase the transverse width thereof in the direction of pull of the needles the employment of oval needles I00 causes the resultant openings to have a substantially round form as shown at 502 in Fig. 11.

Although the present invention is especially adapted to provide materials of or involving uncured rubber or the like with tiny openings or breathing pores, and is especially advantageous for that purpose, it may however be employed advantageously to perforate rubber that is already cured or to perforate fabric with coatings or laminations other than rubber. While I have shown and described my invention in a preferred form, I am aware that various changes and modifications may be made without departing from the principles of my invention, the scope of which is to be determined by the appended claims.

I claim as my invention:

1. The method of making foraminous sheet material, which comprises providing sheet material composed at least partly of rubber or the like, then forming perforations through the sheet material and simultaneously subjecting said perforation places to isolated applications of heat in a manner to locally soften and preserve the material at the places where the pertrations are made.

2. The method of making foraminous sheet material, which comprises providing sheet material composed at least partly of rubber or the like, then forming perforations through the sheet material and simultaneously subjecting said perforation places momentarily to isolated applications of heat in a manner to locally soften and preserve the material at the places where the perforations are made.

3. The method of making foraminous sheet material, which comprises providing sheet material composed at least partly of rubber or the like, inserting spaced heated sharp pointed needles through a generally unheated area of the sheet and withdrawing the needles therefrom before the area is heated generally.

4. The method of making foraminous sheet material, which comprisesproviding sheet-material composed at least partly of rubber or the like, inserting spaced heated needles through the sheet material to form perforations therethrough, and supplying a cooling medium to the vicinity of the perforations to localize the heat at the perforations.

5. The method of making foraminous material, which comprises providing sheet material composed at least partly of uncured rubber or the like, and forming perforations through the sheet material and simultaneously preservatively conditioning the rubber locally at the perforations.

6. The method of making foraminous material, which comprises providing sheet material composed at least partly of uncured rubber or the like, and forming perforations through the sheet material and simultaneously imparting locally to the rubber at the perforations a partial cure, and thereafter subjecting the rest of the sheet to a curing operation.

7. The method of making foraminous sheet material, which comprises providing sheet material composed at least partly of rubber or the like, inserting spaced needles through the sheet material and heating thevne'edles intermittently in selected timed relation with the insertion thereof.

8. In a perforating device of the class described, the combination of a worksupport, a group of needles reciproeable to and from the support to perforate material thereon, heating means for the needles, and a controller for regulating the temperature of the needles. 7

9. In a perforating device of the class described, the combination of a work support, a plurality of heated needles operable to and from the support to perforate material thereon, and means adjacent the perforating zone constructed and arranged to localize the heat of the needles at the places where the. needles perforate the work on the work support, said means including facilities through which a cooling medium is circulated in proximate spaced relation to the perforating zone,

10. In a perforating device of the class described, the combination of a work support, a plurality of heated needles operable to and from the support to perforate material thereon, and a pair of rollers operable for advancing the work across the support after each perforating operation of the needles, said support and one of the rollers having grooves in the planes of the needles.

FRANK JERMAIN CHANDLER. 

